The Department of Education said that, while students with disabilities make up 12 per cent of students in public schools, they make up 75 percent of the students who are physically restrained by adults in their schools.

In 2008, a 12-year-old boy was filmed being taken away in handcuffs after throwing sticks at a pregnant guidance counsellor at his school in Orlando, Florida.

A mug shot showed the little boy in tears. He was charged with battery.

In the latest incident, a sheriff’s deputy has been accused of handcuffing an eight-year-old boy and a nine-year-old girl at schools in Kansas. Both of the children have ADHD and were punished after failing to do as staff members told them.

“If you want the handcuffs off you're going to have to behave or ask me nicely,” the deputy can be heard telling him.